LouieM

The latest issue of Corvette Fever has an article on Red Devil brakes. The rotors are of titanium/cermic, and Red Devil sells its own brake pads. These reduced a C5s 60-0 braking distancefrom 125 feet to 85 - 99 feet. This is astounding! The article says similar brakes are available for 65 and up Vettes. The Red Devil web site (reddevilbrakes.com) says to "ask" about C3 and C4 rotors/pads/calipers. If these brakes fit a C3 they should fit a C2. Can any of the engineers here chime in with opinions on whether these brakes are really that good? C5 front rotors cost $1,100-1,200 EACH, rears are $100 cheaper. Pads just for the front calipers would be about $250. Nothing cheap there, but if they work I'd add them to my 67. I'd rather stop 50 shorter than have another 50 hp. Anyone heard of these brakes before, or used them?

K2

Good brakes are important but there is a point of diminishing returns when spending money on brakes. As long as you have sufficient brake force to lock up the brakes, the stopping distance is more a function of the relative co-efficient of friction of the rubber tire surface and the road surface. One very important component in achieving the shortest stopping distance (with out anti-lock control) is the ability to modulate the braking force effectively so as not to lock up the brakes, but to achieve that point of maximum braking which occurs just prior to lthe point of lock-up. If these brakes help you to control brake force to more easily find and hold that point, they will shorten your stopping distance. If not, I would say their cost might not be justified. If you can lock your brakes you have enough brake force but might benefit from experimenting with different linings that modulate better or try proportioning the front / back braking bias. This can get dicey as different road or weather conditions will make this a moving target. The factory system is engineered with the appropriate bias for a wide range of average driving conditions.

bcwaller

I'm confused how they can get a significant improvement like that just from changing the pads. Even with new pads/calipers/rotors the car is not running out of brakes at any time during a single 60-0 stop. Now, work the car over in a 45 minute lapping session and I can see pads and other equipment making a huge difference in resisting fade, bleeding away heat, etc.

Maybe if the test was really a torture test where they did 50 back to back 100-0 stops and then measured 60-0 on the last stop I could see their fancy brakes making a difefrence like this.

SWCDuke

Braking performance is usually limited by tires, not brakes, and this includes vintage Corvette drum and disk systems. If brakes were the limiting factor you would not be able to lock up the wheels, and if you can't lock up the wheels on your Corvette, there is something wrong with the brakes!

Surface adhesion is also a big factor. For example, polished concrete has poor adhesion, fresh grainy concrete is fairly good, and certain "seasoned" asphalts are the best. On any modern car, tire and surface characteristics are what determine brake performance, not the brake system.

C5s are among the best braking vehicles currently produced. The Z06 in particular is among the top handful because of the sticky GY Eagle F1 Supercar Tires and dynamic proportioning.

Porsche 911s, in particular, have always been excellent brakers because they usually have sticky tires, well designed and sorted brake hardware, and the rear weight bias provides a theoretical advantage by not overloading the front tires. Under 1g braking a 911 has just about 50/50 weight distribution, so the front tires are not overloaded with the rear tires doing nothing like on a typical FWD car.

Check out Road and Track's current test summary page to see which modern cars excel at braking performance, They usually use the same test venue (Pomona) under similar weather conditions, so the results are reasonably comparable.

Given the above, I have to cast a jaundiced eye on the published test data. Given enough motivation I can come up with tests to prove whatever you want to prove.

Duke

LouieM

My non-engineer brain is simply unclear how they can get such a reduction in stopping distance with only a change of all four rotors and pads -- basically changing materials. They used the same 2001 C5 with the Active Handling turned off and did six stops with the stock brakes and then six with the Red Devils, with a 30-minute cooloff between runs. ABS means the brakes aren't locked, so I suppose threshhold breaking is maintained all the way fro 60 to 0, unlike in the old crocks, I mean classics, we drive. I'll be interested to hear some real-world stories, prob. from C5 guys. One more mysterious car thing.

SWCDuke

Active handling and ABS perform separate functions. "Competition mode" in C5 disables active handling, but not ABS. In fact, IIRC I don't think ABS can be disabled from the cockpit in a C5, so I will assume the tests were conducted with ABS.

Late model C5s have dynamic proportioning built into the ABS, which works to individually maximize the contribution of all four tires to deceleration for any global or local traction coefficient.

The best way to panic stop in a modern car is to just stomp on the pedal as hard as you can and steer as necessary. A monkey could to it as good as you or me.

The car mags have done tests with ABS on and off on various cars and on-average their test drivers, who are experts and do these tests all the time cannot better ABS stops on normal pavement.

So you're saying they did the test on the OE pads, swapped the pads and reran the test with the same car a half hour later and reduced the distance over 20 percent?!

This just doesn't pass my smell test!

Duke

LouieM

They swapped not just the pads, but installed four of Red Devil's titanium/ceramic rotors too, which seembe the heart of the system.

JohnZ

Marketing hogwash - I smell a linkage between the advertising and editorial departments; with ABS and a max pedal pressure stop (so the ABS is fully engaged), the tires stop the car, not the whizbang rotors. I continue to be amazed by folks who spend $5,000 for cryo'd/slotted/cross-drilled/miracle-metal rotors and powder-coated billet polished-and-pastel calipers for the Saturday cruise-in crowd to ogle that won't stop the car any faster on the street than the (excellent) stock system.

Of course, if your C5 already has all the trinkets-and-jewelry stuff and carbon fiber ashtray lids and sill plates from all the catalogs, I guess $5,000 worth of pretty brakes is the only area left to "personalize" the car with bolt-on stuff.

"Marketing, son, marketing.....that's where the money is"

LouieM

So, can I assume that the answer to my original question is "No"?

SWCDuke

I think the "record" achieved here was time required to swap rotors and pads on a C5.

Duke

winstonc

The rotors are significantly lighter, less rotating mass. Just like a lighter wheel, faster acceleration and deceleration.

IMO.

Avispa

Answers here are only half right. True that the ultimate amount of braking force available is limited by the tire friction to the road, but that is not the only factor in how well the car stops. The other factors are the coefficient of friction between the pad and rotor, the amount of force that can be applied by the calipers to the pads, and how well the force can be controlled (or modulated as K2 says). This last factor is the one that has the most effect on how much braking force you have available BEFORE the brakes lock up. The relationship between braking force and caliper force is supposed to be linear, but in practice it is not because of factors such as gases being trapped between the pad and rotor and temperature change in the pad and rotor during braking, among others. The fact that the brakes can be locked up doesn't directly correlate to the performance of the braking system. 63s and 64s with drum brakes lock up very well, thank you. Are you seriously going to tell me C2 disk brakes weren't a substantial improvement in braking performance over drums (and I don't just mean fade resistance)?

Certain types of high coefficient of friction brake pads, even with stock rotors and tires, will make a noticeable difference in how well the car brakes without locking up. Put a set of Hawk carbon metallic pads on your C2 and tell me this isn't true.

Better yet, try an experiment with a more modern car with ABS. Put the same set of tires on a 2003 Mustang GT and a 2003 Cobra, hammer the crap out of the brakes on both, then come back and tell me the brake components don't make a difference. John Z, I've owned both of these cars and the improvement in stopping power of the big Brembos on the front of the Cobra is dramatic.

Having said all that, I don't think that the rotor material is anywhere near as important as the pad material. The Red Devil calipers are made to resist heat caused warping, not really to increase friction. All the holes and slots are intended to vent trapped gases to improve modulation, but in practice they can have the effect of making the rotors more susceptible to warping. So, all the heat treatment and exotic materials.

Hitch

Holy old post Batman!!! 2004... Talk about going way back...

workmanw

Yes, this is a really old thread but very relevant topic. A major factor that all of the responders missed is that the titanium rotors shaved 33 lbs of un-sprung weight off of each wheel, that's huge! Losing that much rotational mass probably accounted for the shorter stopping distances more than anything else. They still sell the brakes and the price no longer seem so out of line if compared to carbon ceramic brake kits.

bcwaller

Really old thread, and their Web site is dead, so I would think twice here...

Bill32

I was very lucky to get to compare the cast iron 911 brakes to the carbon ceramic on a similar (sort of) 911. Got to drive both cars, one right after the other. I've been a driving instructor for 18 years and race open wheel so, I know how to use the brakes.

The first was a 911 GT3 Cup (street licensed) with cast iron. As you said, very impressive.

The second car was a 911 GT3 4.0 with a carbon ceramic setup (cost wise makes the red devil look nickel/dime). Very, very few of the GT3 4.0's made it in to the U.S.
The difference in braking performance was huge.

As to this thread, would I spend the red devil kind of money on a street Corvette, no way.
When my 67 goes back on the road, all it will get is upgraded pads.

PAmotorman

I know jerry "harpo" martino the owner and that is all I will say. the titanium rotors do save weight

GTOguy

The less unsprung weight, the better. Much better. That said, unless you have ABS, once those wheels are locked, they are locked.....stopping distance will depend on the rubber in the tire, the road, the temps, the weight, the angle, and on and on. My tip of the day: drive defensively, and don't tailgate!!!

Westlotorn

If you have ever seen brake manufacturing it takes huge investment. Small companies generally can't do that.
Testing is done for NVH and for stopping power and modulation on expensive Dynos that test brakes. Very expensive stuff.
China is courting anyone with a dollar to supply them with any brake product you can ask for. Do they deliver??? Try and see.

On the brake test comparisons on the track in this thread, did you guys notice better brakes on the first stop or after the brakes were worked and hot? Larger better brakes would start to shine after the first couple stops and continue to show advantage with every consecutive stop. No surprise, larger rotors run cooler = Better brakes from the first stop to the last stop.
From my experience if your not racing you should be happy with stock type materials.
They have been tested professionally to work in your car.

rfn026

The best place for brake pad advice will be from the people who actually make the brake pads. But - you have to have some data to help them.

Are you simply driving around town? Or, are you running track events?

Do you want to run the same compound on both the front and rear?

Here's an article I wrote last year about all of this. It's geared mainly to the racer and the track junkie but the information is still useful for a street driven car.

Richard Newton